java - Inject bean at runtime reading properties file -

suppose have class mailconsoleservice , class mailsmtpservice, both implement mailservice interface. have class emailjob loads users db , send email through mailservice instance injected spring.

how read properties , determine @ runtime implementation of mailservice inject? properties change @ time app running, obviously.

i've thought create factory bean returns right instance spring container emailjob don't know how implement this.

note: beans configured singleton scope, guess i'll have change prototype emailjob @ least.

note 2: in factory bean how avoid read properties file each time?

thanks!

i not sure understood question. based on understood, if bean @ runtime properties file , file changed @ runtime, below 1 way of doing this. need handle app context , bean name properties file.

the prototype scope has nothing this. if declare bean of type prototype means new bean instance everytime ask app context it.

@component public class emailjob {        @autowired     private applicationcontext appcontext;      public void sendemail(){          mailsender mailsender=(mailsender)appcontext.getbean(<get bean name properties file>);          // remaining things     }   }